//=======================================================================
// Copyright 1997-2001 University of Notre Dame.
// Authors: Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================

#error \
    "This example appears to be incorrect; it uses edge weights that are smaller than 0 using the comparison operator passed to Dijkstra's algorithm, which is not allowed."

#include <boost/config.hpp>
#include <iostream>

#include <boost/graph/graph_traits.hpp>
#include <boost/graph/graph_utility.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/dijkstra_shortest_paths.hpp>
#include <boost/graph/visitors.hpp>
#include <boost/graph/transpose_graph.hpp>

/* Output:

  distances from start vertex:
  distance(a) = 0
  distance(b) = 3
  distance(c) = 1
  distance(d) = 3
  distance(e) = 3

  min-max paths tree
  a --> c
  b -->
  c --> d
  d --> e
  e --> b

*/

int main(int, char*[])
{
    using namespace boost;

    typedef adjacency_list< listS, vecS, directedS, no_property,
        property< edge_weight_t, int > >
        Graph;
    typedef graph_traits< Graph >::vertex_descriptor Vertex;

    typedef std::pair< int, int > E;

    const char name[] = "abcdef";

    const int num_nodes = 6;
    E edges[] = { E(0, 2), E(1, 1), E(1, 3), E(1, 4), E(2, 1), E(2, 3), E(3, 4),
        E(4, 0), E(4, 1) };
    int weights[] = { 1, 2, 1, 2, 7, 3, 1, 1, 1 };
    const int n_edges = sizeof(edges) / sizeof(E);
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
    // VC++ can't handle iterator constructors
    Graph G(num_nodes);
    property_map< Graph, edge_weight_t >::type weightmap = get(edge_weight, G);
    for (std::size_t j = 0; j < sizeof(edges) / sizeof(E); ++j)
    {
        graph_traits< Graph >::edge_descriptor e;
        bool inserted;
        boost::tie(e, inserted) = add_edge(edges[j].first, edges[j].second, G);
        weightmap[e] = weights[j];
    }
#else
    Graph G(edges, edges + n_edges, weights, num_nodes);
    property_map< Graph, edge_weight_t >::type weightmap = get(edge_weight, G);
#endif

    std::vector< Vertex > p(num_vertices(G));
    std::vector< int > d(num_vertices(G));

    Vertex s = *(vertices(G).first);

#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
    dijkstra_shortest_paths(G, s, &p[0], &d[0], weightmap, get(vertex_index, G),
        std::greater< int >(), closed_plus< int >(),
        (std::numeric_limits< int >::max)(), 0, default_dijkstra_visitor());
#else
    dijkstra_shortest_paths(G, s,
        distance_map(&d[0]).predecessor_map(&p[0]).distance_compare(
            std::greater< int >()));
#endif

    std::cout << "distances from start vertex:" << std::endl;
    graph_traits< Graph >::vertex_iterator vi, vend;
    for (boost::tie(vi, vend) = vertices(G); vi != vend; ++vi)
        std::cout << "distance(" << name[*vi] << ") = " << d[*vi] << std::endl;
    std::cout << std::endl;

    std::cout << "min-max paths tree" << std::endl;
    adjacency_list<> tree(num_nodes);

    for (boost::tie(vi, vend) = vertices(G); vi != vend; ++vi)
        if (*vi != p[*vi])
            add_edge(p[*vi], *vi, tree);

    print_graph(tree, name);

    return 0;
}
